The purification of small biological and chemical samples has become increasingly common in biotechnological and biomedical research. Due to the high numbers of small sample volumes, many highly sensitive analytical methods have been developed. A number of methods such as dialysis, spinning samples through filtration membranes or using spin columns filled with different absorption materials, are among the most common techniques for purifying and separating small sample volumes.
Spin columns are small columns that purify and/or separate the components of a sample by centrifugation. The columns are made of a tube in which solid column material is held in place by a filter or fritte at the base of the column. The sample is introduced at the top of the column and centrifugation results in the purification or component alteration of the sample as it passes through the solid matrix. Through this method, undesired molecules can be removed from a sample by using adsorption gel filtration, ion-exchange, affinity separation and similar methods.
Currently, many different types of spin columns with different fittings at their ends, are available in the market. However, there are no spin columns with uniform fittings currently available in the market so that, the columns can not be securely interconnected or joined together with other columns to allow versatility in the preparation and purification of samples. This method allows a combination of different columns for one-step purification.
The present invention describes the use of standard luer fittings at the top and the bottom of spin columns. The two types of luer fittings, screw and slide-in, both create secure and strong seals when two luer fittings are joined together.
One of the main advantages of luer fittings is that multiple columns can be attached to each other for the one-step purification of samples. This process will lead to faster sample preparation since a sample can directly move from the bottom of one column to the top of the next column. Furthermore, sample loss is minimized since a sample does not need to be transferred from one column system into another column system for each purification or sample separation step.